CVE-2025-23205: jupyter nbgrader Exposure of Resource to Wrong Sphere

Vulnerability summary

CVE-2025-23205 is a medium (CVSS 6.9) Exposure of Resource to Wrong Sphere vulnerability in jupyter nbgrader. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 39.3% of scored vulnerabilities.

Timeline

1. 17-01-2025
   PublishedVulnerability first disclosed.
2. 06-02-2025
   Last modifiedVulnerability information updated.

Description

nbgrader is a system for assigning and grading notebooks. Enabling frame-ancestors: 'self' grants any JupyterHub user the ability to extract formgrader content by sending malicious links to users with access to formgrader, at least when using the default JupyterHub configuration of `enable_subdomains = False`. #1915 disables a protection which would allow user Alice to craft a page embedding formgrader in an IFrame. If Bob visits that page, his credentials will be sent and the formgrader page loaded. Because Alice's page is on the same Origin as the formgrader iframe, Javasript on Alice's page has _full access_ to the contents of the page served by formgrader using Bob's credentials. This issue has been addressed in release 0.9.5 and all users are advised to upgrade. Users unable to upgrade may disable `frame-ancestors: self`, or enable per-user and per-service subdomains with `JupyterHub.enable_subdomains = True` (then even if embedding in an IFrame is allowed, the host page does not have access to the contents of the frame).

• CWE-668Exposure of Resource to Wrong SphereThe product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.